Trailer towing system

ABSTRACT

An accessory towing apparatus that connects a towing vehicle to a gooseneck-type trailer. The accessory towing apparatus includes a chassis framework assembly mounted on an axle having two ground engaging wheels. The chassis assembly includes three linkage arms, which are attached to and extend from the framework. The ends of the three linkage arms are designed to engage and couple with three brackets attached to the main frame of the towing vehicle. When the respective coupling mechanism of the three linkage arms are each engaged, they are substantially parallel to one another and pivot about a substantially common axis. An automatic alignment and attachment system may also be included to greatly simplify the attachment process of the gooseneck-type trailer to the towing vehicle.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent applicationSer. No. 11/249,100 filed on Oct. 12, 2005, now U.S. Pat. No. 7,497,457which claims the benefit of and priority to a U.S. Provisional PatentApplication No. 60/617,836 filed Oct. 12, 2004, the technical disclosureof which is hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Technical Field:

The present invention relates to a trailer towing system and moreparticularly to an improved towing apparatus used to connect a towingvehicle and a gooseneck-type trailer, whereby the improved towingapparatus enhances the utility, stability, maneuverability and safety ofthe hitched vehicle and trailer.

2. Description of the Related Art:

As shown in FIG. 1 a, a towing mechanism such as a simple bumper hitch12 is frequently added to a vehicle 10 for the purpose of towing atrailer 20. However, such a bumper pull trailer can oftentimes place anexcessive vertical load on the back end of the towing vehicle 10.Moreover, such draw bar trailers have inherent stability and weighttransfer problems due to the towing pivot point being positioned behindthe rear axle of the towing vehicle 10.

A more recent innovation in trailer towing systems includes what arecommonly referred to as gooseneck trailer rigs and fifth wheelrecreational vehicle (RV) trailers (hereinafter referred to collectivelyas “gooseneck-type trailers”). As shown in FIG. 1 b, gooseneck trailerrigs typically include a trailer 50 having an extended forward sectionwith a vertical tongue 52 extending therefrom. The vertical tongue 52 isadapted to be coupled to a hitch mechanism 44, which is secured to andsupported by a suitable frame mechanism attached to the bed 42 of apick-up truck 40. The hitch mechanism 44 is typically mounted onto thebed of the truck above and slightly forward of its rear axle. A couplermechanism, located at a distal end of the vertical tongue 52, pivotallyattaches the vertical tongue 52 to a fixed ball portion of the hitchmechanism 44.

Fifth wheel RV trailers are very similar to gooseneck trailer rigs buthave much shorter vertical tongues and typically require a raised hitchmechanism on the tow vehicle. While a gooseneck trailer hitch usuallyincludes a ball hitch mechanism mounted onto the bed of the towingvehicle and a corresponding coupler mechanism on the distal end of thevertical tongue, the fifth wheel hitch mechanism typically comprises ahitch plate mechanism mounted onto the bed of the towing vehicle andoperable for receiving a disc-shaped coupler on the end of the verticaltongue commonly referred to as a kingpin.

Gooseneck-type trailer systems offer a number of advantages over thebumper pulled or draw bar trailers. By virtue of its geometry, agooseneck-type trailer rig is typically able to safely tow greater loadsthan a similarly sized bumper pulled trailer because the load is passeddirectly onto the rear axle of the truck instead of onto the bumper.Moreover, by positioning the pivot point of the trailer nearly over therear axle, gooseneck type trailer rigs distribute the load more evenlyover the tow vehicle, causing less wear and tear on the tow vehicle anda smoother ride. In addition, gooseneck type trailer rigs also offer asmaller turning radius.

While current gooseneck type trailer rigs offer improved stability overbumper pull trailers, they also have several disadvantages. In general,gooseneck type trailer rigs are only suitable for use with a pick-uptruck style towing vehicle. Moreover, the storage capacity of thepick-up bed is greatly diminished while the gooseneck type rig isattached to the towing vehicle. In addition, when detached from thetowing vehicle, supporting legs or jack stands must be extended tosupport the forward portion of the trailer rendering the gooseneck typetrailer essentially immobile. The reattachment of the gooseneck typetrailer to a towing vehicle can also be inordinately complex anddifficult. What is needed is an improved trailer towing system whichfully exploits the usefulness of the gooseneck type trailer whileminimizing its inherent shortcomings.

Another problem area with all trailer towing systems involves braking.While four wheel brakes are mandatory for vehicles and combinations ofvehicles over 10,001 lbs., many lighter trailers have no brakes. This isparticularly critical with regard to gooseneck type trailers, which aretypically larger. With insufficient or no brakes, a trailer will pushagainst the tow vehicle every time it decelerates to stop. Moreover, ifthere is a sway, the trailer can jackknife because there is nothing tocontrol it. Thus, larger trailers are typically equipped withrudimentary braking systems. There are basically three types of trailerbraking systems currently available: electronically controlled electricbrakes, hydraulically controlled electric brakes, and surge hydraulicbrakes. Electronically controlled electric brakes provides automatic andmanual control of electric trailer brakes and require the towing vehicleto be equipped with controlling device and additional wiring forelectrical power. Hydraulically controlled electric brakes are electricbrakes which are applied in proportion to brake pedal pressure appliedin the towing vehicle. Surge brakes are independent hydraulic brakesactivated by a master cylinder at the junction of the hitch and trailer.Thus, current trailer braking systems are highly dependent upon thetowing vehicle for either electrical power or hydraulic power.Therefore, a need exists for an improved trailer towing system havingenhanced braking and stability capabilities. Moreover, it would bedesirable to produce an improved trailer towing system having anindependent trailer braking capability and providing enhanced stabilityto the both the trailer and the towing vehicle.

SUMMARY OF THE INVENTION

The present invention overcomes many of the disadvantages of prior arttowing systems by allowing gooseneck-type trailers to be towed by avariety of motor vehicles. Moreover, the present invention allows agooseneck-type trailer to be towed without diminishing the storagecapacity of the towing vehicle. In addition, the present inventionimproves the stability and mobility of a gooseneck-type trailer, bothwhile attached to and detached from the towing vehicle. Furthermore, thepresent invention includes a novel apparatus and method that greatlysimplifies the reattachment process of the gooseneck-type trailer to thetowing vehicle.

The improved system includes an accessory towing apparatus used toconnect the towing vehicle and gooseneck-type trailer. The accessorytowing apparatus effectively extends the towing vehicle's wheelbasethereby enhancing stability and control. Moreover, when properlysecured, the axle of the accessory towing apparatus is aligned parallelwith the traction axle of the towing vehicle further enhancing thestability and control of the towing assembly. The accessory towingapparatus also prevents the overloading of the back end of the towingvehicle, which can induce poor steering and traction control, andbraking ability. Indeed, by absorbing the vertical load of thegooseneck-type trailer, the accessory towing apparatus allows a smallersized towing vehicle to be used safely.

In one embodiment, the accessory towing apparatus includes a chassis orframework assembly mounted to an axle having at least two groundengaging wheels. The chassis includes three linkage arms, which areattached to and extend from the framework assembly. The distal ends ofthe three linkage arms each include coupling mechanisms which aredesigned to engage complimentary coupling mechanisms connected to themain frame of the towing vehicle. When the respective coupling mechanismof the three linkage arms are each engaged, they are substantiallyparallel to one another and pivot about a substantially common axis. Inone embodiment, the coupling mechanisms comprise heavy-duty gatelatching mechanisms, which couple with horizontal gate rod assembliesattached to the main frame of the towing vehicle. Each gate latchingmechanism includes a latch assembly partially enclosed within andpivotally attached to a bracket assembly having a V-shaped groove foraccepting the horizontal gate rod assembly. The latch assembly mayfurther include a number of notches, which allow the latching mechanismto be secured in either an opened or closed position.

In another embodiment, the accessory towing apparatus may furtherinclude an automatic alignment and attachment system. The alignment andattachment system comprises two lengths of cable or chain, which arealigned with the two outboard linkage arms and connected to a winchmechanism. The loose or distal ends of the chains are operable forselective attachment to the main frame of the towing vehicle.

In a preferred embodiment, the two lengths of cable or chain areconnected to a common yoke mechanism, which is slidably coupled to eachof the two outboard linkage arms and connected to a single winchmechanism. The winch mechanism is preferably a ratcheting winchmechanism that is self-contained and integral to the accessory towingapparatus and may be powered and controlled mechanically, electrically,hydraulically or any combination thereof. The two chains or cables areof equal length and adequately spaced apart, such that when the cablesare attached to a tow vehicle the centerline of the accessory towingapparatus (and correspondingly, the trailer) is aligned with thecenterline of the tow vehicle by simply driving the tow vehicle straightforward a short distance. The winch mechanism may then be used to drawand guide the ends of three linkage arms into their respective couplingattachments attached to the towing vehicle.

In a preferred embodiment of the automatic alignment and attachmentsystem, the latching mechanisms on the two outboard linkage armscomprise the heavy-duty gate latching mechanism described previously,while the latching mechanism for the center linkage arm comprises acompression latch mechanism, which, in conjunction with a roller rampassembly attached to the tow vehicle, assists in aligning the couplingmechanisms on the linkage arms with their respective attachment pointson the towing vehicle. This embodiment is particularly useful whenattaching the accessory towing apparatus on uneven ground.

Moreover, the accessory towing apparatus may further comprise asecondary or accessory winch having a longer cable that is operable forproviding a self-extraction capability. For example, when the trailer ispositioned in a sandy or soggy area having poor traction, the towingvehicle can be positioned on solid footing and the secondary winch maybe used to pull the accessory towing apparatus and trailer towards thetowing vehicle. When the trailer is close enough to the towing vehicle,the cables of the alignment and attachment system may then be connectedto draw and guide the ends of three linkage arms the remaining distanceinto their respective latching mechanisms.

In accordance with another feature of the invention, the accessorytowing apparatus may further comprise a novel automatic wheelretraction/extension system. The wheel retraction/extension systemactuates in conjunction with a compression latch mechanism toautomatically retract and extend a jockey wheel assembly. Thecompression latch mechanism is mechanically linked with the jockey wheelassembly that is pivotally attached to a linkage arm of the accessorytowing apparatus. As the compression latch mechanism is compressed intoits sleeve housing, an attached cam mechanism induces a torquing momenton the jockey arm assembly causing it to rotate about its pivot point.The compression latch mechanism is biased as it is compressed into itssleeve housing, so that when the accessory towing apparatus isdisengaged from the towing vehicle, the compression latch mechanismautomatically expands out of its sleeve housing, thereby causing thejockey wheel assembly to automatically extend. The compression latchmechanism may also include a biased interlock mechanism for preventingthe jockey wheel from retracting whenever the accessory towing apparatusis detached from the towing vehicle

Another feature of the invention comprises a novel receiver hitchmechanism attached to the framework of the towing vehicle. The receiverhitch mechanism includes a framework, which is securely attached to thechassis frame of a towing vehicle, and three receiver sockets or boxes,which are co-aligned along a common axis. The receiver sockets are eachoperable to selectively receive a latching mechanism. A retention boltmay be utilized to selectively attach each latching mechanism to itsrespective receiver socket. Thus, when not in use, the various latchingmechanisms may be removed from their respective receiver sockets forsafe keeping.

In accordance with another feature of the invention, the axle assemblymay also include a power take off mechanism to power a hydraulic pumpassembly, a vacuum pump assembly, and/or an accessory electricalgenerator. The independent hydraulic and vacuum pump assembly enablesthe accessory towing apparatus to provide hydraulic braking power to alltrailer wheels that is independent of the towing vehicle's hydraulicbraking system. In addition, the accessory hydraulic pump can be used tocharge a hydraulic pressure accumulator thereby providing accessoryhydraulic power for a hydraulic powered ratcheting winch mechanism.Likewise, the electrical generator enables the accessory towingapparatus to provide accessory electrical power to itself and thetrailer that is independent of the towing vehicle's electrical system.Additionally, the accessory electrical generator can be used to chargean accessory battery on the accessory towing apparatus, which can supplyemergency or back-up electrical power to the towing vehicle.

Thus, the accessory towing apparatus of the present invention offers anumber of advantages over previous towing apparatus. The accessorytowing apparatus effectively extends the towing vehicle's wheelbasethereby enhancing stability and control. Moreover, it eliminates theoverloading of the back end of the towing vehicle that induces poorsteering control and braking ability. Indeed, by absorbing the verticalload of the gooseneck-type trailer, the accessory towing apparatusallows a smaller sized towing vehicle to be safely used. Furthermore, itadds an additional axle to aid in braking.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the method and apparatus of the presentinvention may be had by reference to the following detailed descriptionwhen taken in conjunction with the accompanying drawings, wherein:

FIG. 1 a is a side view of a prior art bumper hitch towing system;

FIG. 1 b is a side view of a prior art gooseneck-type towing system;

FIG. 2 is perspective view of the improved trailer towing system of thepresent invention;

FIG. 3 a is a perspective view of the accessory towing apparatus of thepresent invention;

FIG. 3 b is cut-away perspective view of the accessory towing apparatusof the present invention shown in FIG. 3 a;

FIG. 3 c is an overhead plan view of the accessory towing apparatus ofthe present invention shown in FIG. 3 a;

FIG. 3 d is a side view of the accessory towing apparatus of the presentinvention shown in FIG. 3 a;

FIG. 4 a is a cross-sectional view of the accessory towing apparatus ofthe present invention shown in FIG. 3 c taken along line 4 a-4 a;

FIG. 4 b is a cross-sectional view of the accessory towing apparatus ofthe present invention shown in FIG. 3 c taken along line 4 b-4 b;

FIG. 5 a is a perspective view of a latching mechanism of the accessorytowing apparatus of the present invention;

FIG. 5 b is a side view of the latching mechanism shown in FIG. 5 adepicting the mechanism in an opened position;

FIG. 5 c is a side view of the latching mechanism shown in FIG. 5 adepicting the mechanism in a closed position while engaged with thehorizontal gate rod assembly of a receiver bracket of the vehiclereceiver hitch of the present invention;

FIG. 6 a is a cut-away overhead view of the compression latch mechanismof the accessory towing apparatus of the present invention;

FIG. 6 b is a cut-away side view of the compression latch mechanism ofthe accessory towing apparatus of the present invention;

FIG. 7 is perspective views of the novel receiver hitch mechanism usedin conjunction with the accessory towing apparatus of the presentinvention;

FIG. 8 is a perspective view illustrating the use of the automaticaligning system of the accessory towing apparatus of the presentinvention; and

FIGS. 9 a-9 b are side views of the accessory towing apparatus of thepresent invention locked and engaged with the towing vehicle;

FIG. 10 is an overhead view of the accessory towing apparatus of thepresent invention locked and engaged with the towing vehicle; and

FIGS. 11 a-11 d are sequenced, cut-away side views of the compressionlatch mechanism being utilized in conjunction with the automatic wheelretraction system of the accessory towing apparatus of the presentinvention.

Where used in the various figures of the drawing, the same numeralsdesignate the same or similar parts. Furthermore, when the terms “top,”“bottom,” “first,” “second,” “upper,” “lower,” “height,” “width,”“length,” “end,” “side,” “horizontal,” “vertical,” and similar terms areused herein, it should be understood that these terms have referenceonly to the structure shown in the drawing and are utilized only tofacilitate describing the invention.

All figures are drawn for ease of explanation of the basic teachings ofthe present invention only; the extensions of the figures with respectto number, position, relationship, and dimensions of the parts to formthe preferred embodiment will be explained or will be within the skillof the art after the following teachings of the present invention havebeen read and understood. Further, the exact dimensions and dimensionalproportions to conform to specific force, weight, strength, and similarrequirements will likewise be within the skill of the art after thefollowing teachings of the present invention have been read andunderstood.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIG. 2, the improved trailer towing system of the presentinvention comprises an accessory towing apparatus 100 used to connect atowing vehicle with a gooseneck-type trailer 250. When attached to agooseneck-type trailer 250, the accessory towing apparatus 100 becomesessentially integral with the gooseneck-type trailer 250, so that, whendetached from the towing vehicle, the gooseneck-type trailer 250 nolonger needs jack stands to remain upright.

As shown in the Figures and in greater detail in FIGS. 3 a-3 d, theaccessory towing apparatus 100 includes a towing chassis assemblymounted on an axle assembly 102 having at least two ground engagingwheels 104 attached thereto. The chassis assembly includes a mainframework assembly 110 mounted over the axle assembly 102 and threelinkage arms 130 a, 130 b, 130 c attached to and extending from the mainframework assembly 110. A plurality of storage boxes 114, 116, 118 mayalso be mounted to or incorporated into the framework assembly 110. Inthe embodiment shown, the main framework assembly 110 is mounted on asuspension system 103 attached to the axle assembly 102. While a leafspring system is depicted, it is understood that the suspension system103 may also comprise coil springs, air springs, struts, anti-sway barsand/or shock absorbers.

The axle assembly 102 may further comprise ground engaging wheels 104having a fixed alignment or a dynamically alignment (i.e., aresteerable). Moreover, the wheels 104 may freely rotate independent ofone another or be connected via a differential mechanism 107. In apreferred embodiment the axle assembly 102 comprises a dynamicallyaligned or steerable axle assembly, which allows the wheels 104 to pivotrelative to the axle assembly 102. At high speeds, a steerable axleassembly allows the wheels 104 to turn slightly in the same direction asthe front wheels of the towing vehicle, which greatly improves trackingof the trailer. But at slow speeds, the steerable axle assembly enablesthe wheels 104 to pivot as much as 23°±1° to the left and 31°±1° to theright in the opposite direction of the front wheels of the towingvehicle. This permits the towing vehicle and attached trailer to make atighter coordinated turns, such as when cornering or getting into atight parking space. Moreover, when attached to the towing vehicle, theaccessory towing apparatus having a steerable or dynamic axle assemblyprevents tire scuffing and enables coordinated turns by automaticallysensing the turning rates and forces generated by the towing vehicle'ssteering mechanism. The steerable axle maintains its alignment with thedrive axle of the towing vehicle, thereby enabling the wheels of theaccessory towing apparatus to follow the track of the rear axle wheelsof the towing vehicle instead of cutting to the inside of the turn. Thisresults in greater maneuverability and improved stability while driving.

In addition, the axle assembly 102 may further comprise a power take-offmechanism 108 for powering accessory systems. The power take-offmechanism 108 may be used to power a hydraulic pump assembly, a vacuumpump assembly, and/or an accessory electrical generator. As shown in theFIG. 3 b, in one embodiment the axle assembly includes a power take offmechanism 108 attached to the differential 107, that that powers anaccessory power mechanism 106. The power generated by the accessorypower mechanism 106 is supplied to appropriate accessory systems locatedon the accessory towing apparatus 100 and/or the attached trailer 250.In one embodiment, the accessory power mechanism 106 comprises ahydraulic pump assembly. In another embodiment, the accessory powermechanism 106 comprises an electrical generator. An independenthydraulic or vacuum pump assembly enables the accessory towing apparatusto provide hydraulic braking power to all trailer wheels that isindependent of the towing vehicle's hydraulic system. In addition, anaccessory hydraulic pump can be used to charge a hydraulic pressureaccumulator (not shown) thereby providing a source of hydraulic powerfor a hydraulically powered ratcheting winch mechanism. Likewise, anelectrical generator could enable the accessory towing apparatus toprovide accessory electrical power to itself and the trailer that isindependent of the towing vehicle's electrical system. Additionally, anaccessory electrical generator could charge an accessory battery (notshown) on the accessory towing apparatus.

The main framework 110 of the accessory towing apparatus 100 furtherincludes a planar surface or saddle 120 upon which a hitch mechanism 124is mounted. The hitch mechanism 124 is typically centered upon thesaddle 120. While a ball hitch mechanism 124 is shown in theillustrations, it is understood that the hitch mechanism 124 mayalternatively comprise a mechanism commonly known as a fifth-wheelhitch. Moreover, the saddle 120 may further comprise a structuralextension framework 122, which extends the hitch mechanism 124vertically above the saddle 120.

The saddle 120 is designed to straddle the longitudinal rails 112 of themain framework assembly 110 and is generally positioned over the axleassembly 102. In one embodiment, the saddle 120 is permanently affixedto the main framework assembly 110 through welding or other similarmeans. However, in a preferred embodiment the saddle 120 is selectivelyaffixed to the main framework assembly 110 by means a bolt assembly.

For example, as shown in FIGS. 3 a-c the saddle 120 includes on itslateral ends a plurality of attachment bolts 126, which correspond to aplurality of longitudinally spaced, vertical alignment holes 128 formedin each of the longitudinal rails 112 of the framework assembly 110. Inthe embodiment shown, the saddle 120 includes three attachment bolts 126on each end which correspond to five alignment holes 128 through each ofthe longitudinal rails 112 of the framework assembly 110. Thus, thelongitudinal position of the saddle 120 relative to the axle assembly102 may be adjusted depending upon which three alignment holes 128 onthe longitudinal rails 112 of the framework assembly 110 are selected.For example, if the three forward-most alignment holes 128 are selected,the saddle 120 will be positioned slightly forward of the axle assembly102, while if the three rear-most alignment holes 128 are selected, thesaddle 120 will be positioned slightly aft of the axle assembly 102.Similarly, if the three center-most alignment holes 128 are selected,the saddle 120 will be positioned directly over of the axle assembly102.

The main framework assembly 110 mounted over the axle assembly 102 isattached to the towing vehicle via three linkage arms 130 a, 130 b, 130c attached to and extending from the main framework assembly 110. Thethree linkage arms 130 a, 130 b, 130 c are fixably attached and integralto main framework assembly 110. In addition, the linkage arms are evenlyspaced and substantially parallel to one another. A lateral crossbar 132may also be attached to the three linkage arms 130 a, 130 b, 130 c toreinforce and stiffen the resulting framework assembly 110.

The distal ends of linkage arms 130 a, 130 b,130 c each include alatching mechanism designed to selectively engage a hitch assembly 220attached to the frame of the towing vehicle 222. The latching mechanismsare aligned so as to pivot about a substantially common axis ofrotation. For example, in a preferred embodiment, the two outboardlinkage arms 130 a, 130 c each include a gate latch mechanism 170, whichpivots about a respective a horizontal bolt 240 on the hitch assembly220. Likewise, the center linkage arm 130 c includes a compression latchmechanism 190, which, when properly aligned and engaged with the hitchassembly 220, pivots about an axis of rotation which is substantiallycommon with that of horizontal bolts 240.

While the preferred embodiment of the accessory towing apparatus 100depicted in Figures includes gate latch mechanisms 170 on the twooutboard linkage arms 130 a, 130 c and a compression latch mechanism 190on the center linkage arm 130 c, it is understood that, depending uponthe particular circumstances, a variety of types of latching mechanismsmay be employed. For example, the distal ends of the three linkage arms130 a, 130 b, 130 c may all include gate latch mechanisms 170, or thecenter linkage arm 130 c could include a gate latch mechanism 170 whilecompression latch mechanisms 190 is used on the two outboard linkagearms 130 a, 130 c. Regardless of which type of latching mechanism isselected, common to all latching mechanisms is that, when properlyengaged with to the hitch assembly 220 attached to the frame of thetowing vehicle 222, they pivot about a substantially common axis ofrotation. Moreover, when the three linkage arms 130 a, 130 b, 130 c areproperly engaged with to the hitch assembly 220, they are essentiallyparallel to one another. Thus, it will further be observed that when thethree linkage arms 130 a, 130 b, 130 c are so engaged, the axle assembly102 is aligned substantially parallel with the traction axle of thetowing vehicle. The accessory towing apparatus 100 securely maintainsthe axle assembly 102 in a substantially parallel alignment with thetraction axle of the towing vehicle during all dynamic operationsfurther enhancing the stability and control of the towing assembly.

With reference to FIGS. 5 a-5 c, close up views of a preferredembodiment of the gate latch mechanism 170 and gate receiver bracket 236are depicted. The gate latch mechanism 170 is operable to engage thegate receiver bracket 236 attached to the vehicle receiver hitch 220.The gate latch mechanism 170 comprises a latch bracket or housing 171comprised of two opposing plates 172 having a latch assembly 180positioned therebetween. The latch assembly 180 is pivotally attached tothe two opposing plates 172 by means of a bolt 183. The latch housing171 also includes a V-shaped jaw 173 formed in the plates 172 and apart-cylindrical recess or seat 174 for receiving the horizontal gaterod assembly 240 of the gate receiver bracket 236 of the hitch assembly220. The two opposing plates 172 are joined at the upper 177 and lower178 portions of the V-shaped bracket jaw 173. The two opposing plates172 further include opposing co-incident holes 175 for receiving alocking pin 176. The latch assembly 180 includes a curved recess surfaceor seat 181 for capturing the horizontal gate rod assembly 240 againstthe seat 174 of the latch housing 171 when the latch assembly 180 ispivoted about the pivot bolt 183. The latch assembly 180 also includes anotch 182 for securing the position of the latch assembly 180 within thelatch housing 171 by means of the locking pin 176.

In FIG. 5 b, the gate latch mechanism 170 is depicted as locked in anopened position in preparation for engaging the gate receiver bracket236 of the hitch assembly 220. The latch assembly 180 has been pivotedabout bolt 183 so as to clear the V-shaped jaw 173 and seat 174 formedin the plates 172. The locking pin 176 inserted through holes 175impinges on a notch 182 a thereby securing the position of the latchassembly 180 within the latch housing 171.

The gate receiver bracket 236 includes a housing comprised of twoparallel-spaced opposing plates 237 having a horizontal gate rodassembly 240 disposed there between. The receiver bracket 236 is fixablyattached to a mounting tongue 234. The lateral spacing between theplates 237 is sufficient to snugly accept the latch housing 171 the gatelatch mechanism 170 with minimal lateral movement. As shown particularlyin FIG. 3 c, the two plates 237 are splayed opened at the open end ofthe receiver bracket 236 in front of the gate rod assembly 240. Thissplayed end portion 238 assists the gate latching mechanism 170 to moresmoothly align and engage the gate receiver bracket 236. The gatereceiver bracket 236 may further include an alignment rod 242 disposedbetween the two opposing plates 237 and incorporated into the lower rearportion of the bracket 236. As will be subsequently explained in greaterdetail, the alignment rod 242 is positioned to accept an alignment chainfrom the accessory towing apparatus 100.

In FIG. 5 c, the gate latch mechanism 170 is depicted in a closedposition while engaged with the gate receiver bracket 236 of the hitchassembly 220. Upon removal of the locking pin 176 from holes 175, thelatch assembly 180 pivots about bolt 183 so as capture the horizontalgate rod 240 of gate receiver bracket 236 between the curved recesssurface 181 of the latch assembly 180 and the curved seat 174 of thelatch housing 171. The locking pin 176 can then be re-inserted throughholes 175 so as to impinge upon a second notch 182 b thereby securingthe latch assembly 180 within the latch housing 171. The latch assembly180 is typically balanced around bolt 183 so as to be biased in a closedposition. It will be observed that the front face portion 184 of thelatch assembly 180 is angled so that when the locking pin 176 isremoved, the latch assembly 180 will automatically open and close aroundthe horizontal gate rod 240 when the gate latch mechanism 170 and gatereceiver bracket 236 are drawn together. In addition, the latch assembly180 may further include an aperture 179 through which an attached strap(not shown) may assist in actuating the latch assembly 180 within thelatch housing 171.

With reference now to FIGS. 4 a, and 6 a-b, an embodiment of thecompression latch mechanism 190 is depicted. In its most basic form, themechanism 190 comprises a roller bearing 191 pivotally attached to aU-shaped roller sleeve 194, which is captured in a sleeve housing 198incorporated into the distal end of a linkage arm. The roller bearing191 is pivotally attached to the roller sleeve 194, by means of a centerpin bolt 192. The roller sleeve 194 is slidably coupled with the sleevehousing 198 along its longitudinal axis. The two side walls of theroller sleeve 194 include slots 196, which ride on stationary bolts 206that are fixably attached to the sleeve housing 198. The slots 196 andbolts 206 prevent the roller sleeve 194 from cocking in the sleevehousing 198 and assist the roller sleeve 194 in translating smoothlywithin the housing 198. The mechanism 190 further comprises a biasingmechanism 204, which is attached between a stationary bolt 206 and arear wall 194 a of the roller sleeve 194. For example, in the embodimentdepicted in the Figures, the biasing mechanism comprises a plurality oftension spring mechanisms, which are each attached between thestationary bolt 206 and a separate eye-bolt 195 attached to the rearwall 194 a of the roller sleeve 194. The biasing mechanism is designedso that its bias force increases as the roller sleeve 194 is compressedor pushed into the sleeve housing 198.

The sleeve housing 198 may also include an alignment slot 200 whichlimits the extent to which the roller sleeve 194 is compressed into thesleeve housing 198. The alignment slot 200 acts as a channel for theends of the center pin bolt 192 which extends laterally away from theroller sleeve 194. The alignment slot 200 is designed so that the rollersleeve 194 may be compressed into the sleeve housing 198 until thecenter pin bolt 192 comes into contact with the rear wall 201 of thealignment slot 200. With reference to the embodiment shown in theFigures and particularly FIG. 3 d, it will be observed that the rearwall 201 of the alignment slot 200 is co-aligned with the curved seat174 of the gate latch mechanisms 170.

The compression latch mechanism 190 is operable to engage a rampreceiver bracket 246 attached to the hitch assembly 220. With referenceagain to the Figures, and in particular FIGS. 3 c and 4 a, thecompression latch mechanism 190 is designed to engage a notch 247 formedin ramp bracket 246 as the accessory towing apparatus 100 is drawntoward the hitch assembly 200. It will be noted that the ramp receiverbracket 246 includes a lower wing 248 extending below and away from thenotch 247 and an upper wing 249 extending above and away from the notch247. These wings assist in engaging and channeling the compression latchmechanism 190 into the notch 247 of the ramp receiver bracket 246 as theaccessory towing apparatus 100 is drawn toward the hitch assembly 200 onan uneven surface.

Thus, as the accessory towing apparatus 100 is drawn closer to the hitchassembly 200, the roller bearing 191 of the compression latch mechanism190 engages a portion of the ramp receiver bracket 246 compressing theroller sleeve 194 into the sleeve housing 198 until the center pin bolt192 impinges on the rear wall 201 of the alignment slot 200. At thispoint, roller bearing 191 is fully seated in the notch 247 and the rampreceiver bracket 246 is captured laterally between the walls of thesleeve housing 198.

With reference again to FIG. 3 c and 3 d, it will be noted that when theaccessory towing apparatus 100 is not engaged with a towing vehicle, thecompression latch mechanism 190 on the distal end of the center linkagearm 130 b extends past the gate latch mechanisms 170 of the two outboardlinkage arms 130 a, 130 c. This permits the compression latch mechanism190 to interact with its respective ramp receiver bracket 246 prior tothe gate latch mechanisms 170 engaging their respective gate receiverbracket 236. Thus, as the compression latch mechanism 190 is channeledtowards the notch 247 of the of the ramp receiver bracket 246, the latchmechanisms 170 of the two outboard linkage arms 130 a, 130 c arecorrespondingly aligned with their respective gate receiver bracket 236prior to each latch mechanism engaging its respective gate receiverbracket 236.

The accessory towing apparatus 100 may also include a jockey wheel 160positioned on one or more of the linkage arms 130 a, 130 b, 130 c forincreased stability when the accessory towing apparatus 100 is detachedfrom the towing vehicle. The arm 164 connecting the jockey wheel 160 tothe accessory towing apparatus 100 may of a fixed or adjustable length.The jockey wheel arm 164 may further comprise a screw jack mechanism(not shown) for retracting the jockey wheel 160 when the accessorytowing apparatus 100 is attached and secured to a towing vehicle. Thejockey wheel arm 164 may also be demountably attached to the accessorytowing apparatus 100 so as to be removable when the accessory towingapparatus 100 is attached and secured to a towing vehicle. The jockeywheel arm 164 may also be pivotally attached to a linkage arms 130 so asto pivotally retract when the accessory towing apparatus 100 is attachedand secured to a towing vehicle.

As shown in FIG. 3 d, the accessory towing apparatus 100 may furtherinclude a tunnel 138 positioned along the topside of a linkage arm 130c, through which a hook 156 and accessory retrieval cable 154 areconnected to an accessory retrieval winch 152 which provides a selfrecovery capability to the accessory towing apparatus 100. The accessoryretrieval winch 152 is preferably self-contained and integral to theaccessory towing apparatus 100 and may be powered and controlledmechanically, electrically, hydraulically or any combination thereof.For example, as depicted in FIG. 3 d, the accessory retrieval winch 152may be located in the forward cargo box 114. The retrieval cable 154 isof sufficient length (e.g., 80 to 100 feet) to enable the accessorytowing apparatus 100 to recover itself and an attached trailer aconsiderable distance. Thus, for example, if an accessory towingapparatus 100 and attached trailer are located in a muddy or sandy area,the accessory retrieval winch 152 and cable 154 allow the accessorytowing apparatus 100 to extract itself to a more suitable area withoutinvolving or jeopardizing the towing vehicle.

With reference now to FIG. 7, an embodiment of the novel receiver hitchmechanism 220 used in conjunction with the accessory towing apparatus100 of the present invention is shown. The receiver hitch mechanism 220includes a receiver hitch framework 224 having three receiver sockets orboxes and comprised of a robust lateral cross member 225 attached andsuspended between two attachment wings 226. The two attachment wings 226are designed to be mounted to the frame 222 of the towing vehicle. Asdepicted in FIG. 7, the two attachment wings 226 are operable forattachment to the main frame structure 222 of the towing vehicle. Inactual practice the attachment wings 226 may be attached through weldingor common fastener means such as nuts and bolts 227 as shown, or may beintegral to the main frame structure 222 of the towing vehicle.

The three receiver sockets or boxes 230 a, 230 b, 230 c are attached tothe lateral cross member 225 of the receiver hitch framework 224 and aregenerally evenly spaced to one another. The receiver hitch framework 224may further include lateral reinforcement members 228 between the threereceiver boxes 230 a, 230 b, 230 c. The receiver hitch framework 224 isdesigned so that, when attached to a towing vehicle, one receiver box230 b is generally centered on the rear of the towing vehicle and thetwo outboard receiver boxes 230 a, 230 c are generally alignedlongitudinally with the main frame structure 222 of the towing vehicle.As shown in the embodiment depicted in FIG. 7, the three receiver boxes230 a, 230 b, 230 c are similarly sized and extend equidistantly awayfrom the rear of the towing vehicle aligned. Moreover, the openings 231a, 231 b, 231 c of the three receiver boxes or sockets are typicallyaligned along a common horizontal axis and vertical plane. While thealignment of the three receiver boxes 230 a, 230 b, 230 c relative toone another may be varied depending upon the circumstances, it isunderstood that the means for attaching the receiver brackets to thereceiver boxes will have to be correspondingly varied so that thelatching mechanisms are co-aligned so as to pivot about a substantiallycommon axis of rotation.

The three receiver sockets 230 a, 230 b, 230 c are each operable forreceiving a receiver bracket mounting tongue 234 and attached receiverbracket 136, 246. Each mounting tongue 234 is selectively secured in itsrespective receiver socket by means of a securing pin 232 insertedthough co-aligned holes 233, 235 in the respective receiver box 230 andmounting tongue 234. When not in use, the receiver bracket assemblies(i.e., mounting tongue 234 and respective attached receiver bracket 136,246) may be removed from the receiver boxes for safekeeping.

Automatic-Aligning and Docking System

With reference to the Figures and in particular FIGS. 3 d and 8, apreferred embodiment of the accessory towing apparatus 100 is shown thatincludes an automatic alignment and docking system. The automaticalignment system includes an alignment yoke mechanism 140, whichconnects an alignment/docking winch 150 with two alignment chains 134 a,134 b, which are selectively attached to the vehicle receiver hitch 220of a tow vehicle. The two alignment chains 134 a, 134 b are ofsubstantially equal length and adequately spaced apart, such that whenthe chains are attached to a tow vehicle the centerline of the trailermay be aligned with the centerline of the tow vehicle by simply drivingthe tow vehicle straight forward a short distance. The alignment/dockingwinch 150 is preferably self-contained and integral to the accessorytowing apparatus 100 and may be powered and controlled mechanically,electrically, hydraulically or any combination thereof. For example, asshown in the embodiment depicted in FIG. 3 d, the alignment/dockingwinch 150 is located in the middle cargo box 116.

The alignment yoke mechanism 140 further comprises a yoke crossbarmember 144 suspended between two yoke sleeves 142. The left yoke sleeve142 a is slidably coupled with the left outboard linkage arm 130 a whilethe right yoke sleeve 142 b is slidably coupled with the right outboardlinkage arm 130 c. The yoke crossbar member 144 maintains the two yokesleeves 142 a, 142 b in a substantially parallel alignment with oneanother. While the yoke crossbar member 144 depicted in the Figures issubstantially straight, it is understood that the yoke crossbar member144 could be of any geometry so long as the two yoke sleeves 142 a, 142b are maintained in a parallel alignment to one another. For example,the yoke crossbar member 144 could be circular and or angular across itslateral extent. A cable 146 attached to the lateral center of to theyoke crossbar member 144 connects the alignment yoke mechanism 140 withthe alignment/docking winch 150. Thus, subject to the length of cable146 deployed from the alignment/docking winch 150, the alignment yokemechanism 140 is free to translate longitudinally along a large extentof the length of the linkage arms.

As depicted in FIG. 3 a, in a preferred embodiment the two alignmentchains 134 a, 134 b are attached to opposing ends of the alignment yokemechanism 140. The two alignment chains 134 a, 134 b are aligned withthe two outboard linkage arms 130 a, 130 c. For example, as depicted inFIG. 3 a, one alignment chain 134 a attached to the alignment yokemechanism 140 is aligned along the underside of the left outboardlinkage arm 130 a, while another alignment chain 134 b attached to thealignment yoke mechanism 140 is aligned along the underside of the leftoutboard linkage arm 130 c. Chain retention brackets 137 located on theunderside of each latching mechanism 170 further assist in maintainingthe alignment of the alignment chain 134 b along the length of itsrespective linkage arm. Moreover, by impinging on their respectivealignment chains as the accessory towing apparatus 100 is drawn towardsthe towing vehicle, the chain retention brackets 137 also help to steerthe accessory towing apparatus 100 into a proper alignment behind thetowing vehicle.

The distal or loose ends of each of the two alignment chains 134 a, 134b include a mechanism 136 for grasping the vehicle receiver hitch 220.For example, in the embodiment depicted in the Figures, the graspingmechanism 136 comprises a hook which may be attached to an alignment rod242 incorporated into the lower portion of a gate receiver bracket 236attached to the vehicle receiver hitch 220.

It is understood that the terms “chain” and “cable” as used in referenceto alignment chains 134 a, 134 b, yoke cable 146, and/or accessoryretrieval cable 154 are used for purposes of identification and not aspecific limitation. Therefore, any suitably strong chain, cable, wireor lanyard would come within the meaning of the term “chain” or “cable”as used with the specification. Moreover, with regard to specificembodiments, the terms “chain” and “cable” may be used interchangeably.Thus, the alignment chains 134 a, 134 b, yoke cable 146, and/oraccessory retrieval cable 154 may in actuality be either chains orcables depending on the specific circumstances.

In an alternate embodiment, a worm screw mechanism contained within alinkage arm (not shown) is used instead of the yoke cable 146 to connectthe yoke mechanism 140 to the alignment/docking winch 150. A single wormscrew mechanism may be attached to the center of the yoke crossbarmember 144 or separate worm screw mechanisms may be attached to the twoyoke sleeves 142.

The automatic alignment system of the subject invention is utilized bypositioning the vehicle receiver hitch 220 of a tow vehicle a shortdistance away from and roughly centered on the front of the accessorytowing apparatus 100, so that the receiver brackets of the vehiclereceiver hitch 220 are roughly aligned with their respective latchassemblies. The alignment/docking winch 150 is energized so that cable146 is spooled out allowing the alignment yoke mechanism 140 to freelytranslate along the length of the outboard linkage arms 130 a, 130 c,thereby allowing the alignment chains 134 a, 134 b to be extended pastthe distal ends of the outboard linkage arms 130 a, 130 c.

As perhaps shown best in FIG. 3 d, in theory the alignment chains 134 a,134 b can be extended past the distal ends of the outboard linkage arms130 a, 130 c approximately the same distance as the length of theoutboard linkage arms 130 a, 130 c. If a greater distance exists betweenthe towing vehicle and the accessory towing apparatus 100, the accessoryretrieval winch 152 and cable 154 described earlier may be utilizedbring the towing vehicle and the accessory towing apparatus 100 withinthe initial engagement limits of the automatic alignment system.

For example, if the accessory towing apparatus 100 and attached trailerare positioned in a soggy area having poor traction, the towing vehiclecan be positioned on solid footing. The accessory retrieval winch 152and cable 154 would first be utilized draw the accessory towingapparatus 100 to within the initial engagement limits of the automaticalignment system.

When the vehicle receiver hitch 220 is positioned sufficiently close tothe accessory towing apparatus 100, the loose ends of the two alignmentchains 134 a, 134 b are attached to the vehicle receiver hitch 220 inpreparation for aligning and docking the accessory towing apparatus 100to the tow vehicle. As shown in FIG. 8, in a preferred embodiment, thetwo alignment chains 134 a, 134 b are each attached to an alignment rod242 incorporated into the lower portion of the respective gate receiverbracket 236 attached to the vehicle receiver hitch 220. The centerlineof the accessory towing apparatus 100 and attached trailer is thenaligned with the centerline of the tow vehicle by simply driving the towvehicle straight forward a short distance.

Upon aligning the centerlines, the tow vehicle is halted in place. Thealignment/docking winch 150 is then energized to reel in the yoke cable146 and draw the alignment yoke mechanism 140 towards the rear of theaccessory towing apparatus 100. The accessory towing apparatus 100 iscorrespondingly drawn toward the vehicle receiver hitch 220 in responseto the movement of the yoke mechanism 140. Thus, the alignment of eachlatching mechanism with its respective complementary receiver bracket ismaintained as the accessory towing apparatus 100 is drawn toward thevehicle receiver hitch 220. Upon securing the latching mechanisms intheir respective receiver bracket, the yoke cable 146 and correspondingalignment chains 134 a, 134 b may be slackened somewhat so as to act astrailer safety chains.

As noted previously, when the latching mechanisms are properly engagedwith corresponding receiver brackets on the hitch assembly 220, thelatching mechanisms pivot about a substantially common axis of rotation.For example, with reference to FIGS. 9 a-b, the embodiment of theaccessory towing apparatus 100 previously depicted in FIGS. 3 a-d isshown having been properly engaged to the hitch assembly 220 attachedthe towing vehicle 252. Upon securing the respective latch mechanismsinto their corresponding receiver brackets, all three linkage arms 130a, 130 a, 130 c freely pivot about a substantially common axis ofrotation. The substantially common axis of rotation is defined by alongitudinal axis extending through the horizontal gate rod assembly 240of the gate receiver brackets 236 and the center pin 191 of thecompression latch mechanism 190. Thus, as depicted in FIG. 9 b, when thetowing vehicle 252 and attached towing apparatus 100 proceed up anincline, the ends of the three linkage arms 130 a, 130 a, 130 c freelypivot about a substantially common axis of rotation, and correspondinglymaintain the alignment of the accessory towing apparatus 100 with thetowing vehicle 252.

Moreover, as shown in FIG. 10, when the three linkage arms 130 a, 130 b,130 c are properly engaged with to the hitch assembly 220, they areessentially parallel to one another. It will further be observed thatwhen the three linkage arms 130 a, 130 b, 130 c are so engaged, the axleassembly 102 of the accessory towing apparatus 100 is alignedsubstantially parallel with the axles 256, 258 of the towing vehicle252. The accessory towing apparatus 100 securely maintains the axleassembly 102 in a substantially parallel alignment with the axles 256,258 of the towing vehicle 252 during all dynamic operations furtherenhancing the stability and control of the towing assembly.

In particular, when the axle assembly 102 of the accessory towingapparatus 100 comprises a steerable axle assembly, described previously,the accessory towing apparatus 100 is able to coordinate its turns inrelation to the towing vehicle. Thus, as depicted in FIG. 10, when thetowing vehicle 252 initiates a turn to the left by turning its frontwheels 254 to the left, as it pulls forward the accessory towingapparatus 100 induce its wheels 104 to turn in an opposite directionrelative to the accessory towing apparatus 100 to coordinate the turn.By maintaining its axle assembly 102 in a substantially parallelalignment with the axles 256, 258 of the towing vehicle 252, theaccessory towing apparatus 100 causes the wheels 104 to pivot or turn inan opposite direction relative to the accessory towing apparatus 100. Asa consequence, the handling characteristics and maneuverability of thecombined towing vehicle 252, accessory towing apparatus 100, andattached gooseneck-type trailer 250 is greatly improved.

Automatic Wheel Retraction/Extension System

Another innovative aspect of the present invention comprises a wheelretraction/extension system used in conjunction with the compressionlatch mechanism to automatically raise and lower the jockey wheelassembly. The automatic wheel retraction/extension system mechanicallylinks the compression latch mechanism 190, described previously, with ajockey wheel assembly pivotally attached to a linkage arm of theaccessory towing apparatus 100. For example, as shown in the Figures, ina preferred embodiment of the subject invention the automatic wheelretraction/extension system is integrated into a compression latchmechanism 190 that is incorporated within the center linkage arm 130 b.

With reference to the Figures, and in particular FIGS. 4 a, 6 a-b, and11 a-d, a preferred embodiment of the automatic wheelretraction/extension system is depicted. The system is comprised of ajockey wheel assembly that is mechanically linked with a compressionlatch mechanism 190. The jockey wheel assembly is comprised of a jockeywheel 160 and connecting arm 164, which is pivotally attached to thelinkage arm 130 b. The alignment of the jockey wheel 160 relative to theconnection arm 164 may be fixed or variable. For example, the jockeywheel assembly may further comprise a caster mechanism 163 which permitsthe jockey wheel 160 to freely swivel about the longitudinal axis of theconnection arm 164. Such swivel-mounted jockey wheel assemblies mayfurther comprise a counter-weight auto center mechanism 162 to bias thealignment of the jockey wheel assembly as it is retracted. Thecounter-weight auto center mechanism 162 is typically positioned belowthe caster mechanism 163 so as to bias the alignment of the jockey wheel160 relative to the connection arm 164 and correspondingly the linkagearm.

The arm 164 connecting the jockey wheel 160 to the accessory towingapparatus 100 may of a fixed or adjustable length. For example, as shownin the Figures, the connection arm 164 may include a fixed member 165,which is pivotally attached to the linkage arm, and an adjustable sleevemember 166, which is slidably coupled to the fixed member 165. Thelength of connection arm 164 is changed adjusted by changing theposition of the adjustable sleeve member 166 relative to the fixedmember 165.

The compression latch mechanism 190 of the automatic wheelretraction/extension system is essentially the same as describedpreviously, with the addition of a cam and downlock assembly thatmechanically links the compression latch mechanism 190 and the jockeywheel assembly. The compression latch mechanism 190 comprises a rollerbearing 191 pivotally attached to a U-shaped roller sleeve 194, which iscaptured in a sleeve housing 198 incorporated into the distal end of thelinkage arm 130 b. The roller bearing 191 is pivotally attached to theroller sleeve 194, by means of a center pin bolt 192. The roller sleeve194 is slidably coupled with the sleeve housing 198 along itslongitudinal axis. The two side walls of the roller sleeve 194 includeslots 196, which ride on stationary bolts 206 that are fixably attachedto the sleeve housing 198. The slots 196 and bolts 206 prevent theroller sleeve 194 from cocking in the sleeve housing 198 and assist theroller sleeve 194 in translating smoothly within the housing 198. Themechanism 190 further comprises a biasing mechanism 204, which isattached to a stationary bolt 206 and a rear wall 194 a of the rollersleeve 194. For example, in the embodiment depicted in the Figures, thebiasing mechanism comprises a plurality of tension spring mechanisms.The biasing mechanism is designed so that its bias force increases asthe roller sleeve 194 is compressed or pushed into the sleeve housing198.

The sleeve housing 198 may also include an alignment slot 200 whichlimits the extent to which the roller sleeve 194 is compressed into thesleeve housing 198. The alignment slot 200 acts as a channel for aportion of the center pin bolt 192 which extends laterally away from theroller sleeve 194. The alignment slot 200 is designed so that the rollersleeve 194 may be compressed into the sleeve housing 198 until thecenter pin bolt 192 impinges on the rear wall 201 of the alignment slot200.

The compression latch mechanism 190 of the automatic wheelretraction/extension system further includes a cam mechanism 214, whichis pivotally attached to the U-shaped roller sleeve 194 and mechanicallylinked with a pin 168 affixed to the connection arm 164 of the jockeywheel assembly. As shown in Figures, in a preferred embodiment, thecompression latch mechanism 190 of the automatic wheelretraction/extension system includes two cam mechanisms 214, each ofwhich are pivotally attached to the roller sleeve 194 and mechanicallylinked with a follower pin 168 affixed to and extending laterally fromthe connection arm 164 of the jockey wheel assembly. The cam mechanism214 is pivotally attached to the roller sleeve 194 by means of a pivotbolt 218 extending laterally therethrough. The follower pin 168 iscaptured in a slot 216 formed in the cam mechanism 214. As the rollersleeve 194 of the compression latch mechanism 190 is pushed back intothe sleeve housing 198, the cam mechanisms 214 eventually apply a forceon the follower pin 168 that causes the arm 164 of the jockey wheelassembly to retract by rotating about a pivot point 167 that pivotallyattaches the jockey wheel assembly to the linkage arm of the accessorytowing apparatus 100.

The automatic wheel retraction/extension system may further comprise adownlock mechanism 208 which prevents the jockey wheel assembly fromretracting prematurely. As shown in the Figures, in one embodiment thedownlock mechanism 208 is pivotally attached to the sleeve housing 198and positioned just above the roller sleeve 194 of the compression latchmechanism 190. The downlock mechanism 208 includes a downlock detent 211and notch 213 to one side of the pivotal attachment point 210 and abiasing mechanism 212 on the other side. The biasing mechanism 212biases the rotation of the downlock mechanism 208 about its pivotalattachment point 210. In the embodiment shown in the Figures, thebiasing mechanism 212 comprises a tension spring mechanism.

With reference now to the Figures and in particular to FIGS. 11 a-d, theoperational sequence of the automatic wheel retraction system will bedemonstrated. As previously noted, the compression latch mechanism 190is designed to engage a ramp receiver bracket 246 attached to the hitchassembly 220. The compression latch mechanism 190 is designed to engagea notch 247 formed in ramp bracket 246 as the accessory towing apparatus100 is drawn toward the hitch assembly 200.

In FIG. 11 a, the jockey wheel assembly of the automatic wheelretraction system is shown in a default or down-and-locked position. Theroller sleeve 194 of the compression latch mechanism 190 is fullyextended from the sleeve housing 198 and there is minimal tension inbiasing mechanism 204. The arm 164 of the jockey wheel assembly is fullyextended and locked in place by means of the downlock mechanism 208. Anotch 213 in the downlock mechanism 208 locks the follower pin 168 ofthe jockey wheel arm 164 in place, thereby preventing the pin 168 fromrotating about the pivot point 167 of the jockey wheel arm 164. Thedownlock biasing mechanism 212 induces the downlock mechanism 208 tomaintain this locked position. The follower pin 168 is also captured ina slot 216 formed in a cam mechanism 214 that is pivotally attached tothe roller sleeve 194.

As described previously, when the accessory towing apparatus 100 isdrawn closer to the hitch assembly 200, the roller bearing 191 of thecompression latch mechanism 190 engages the ramp receiver bracket 246compressing the roller sleeve 194 into the sleeve housing 198. Withreference to in FIG. 11 b, as the roller sleeve 194 is compressed intothe sleeve housing 198, the cam mechanisms 214 are also pushed furtherinto the sleeve housing 198. The follower pin 168 travels along each camslot 216 it is captured within. Eventually, the pivot bolt 218 of thecam mechanisms 214 engages the detent 211 of the downlock mechanism 208.As the roller sleeve 194 is further compressed into the sleeve housing198, the pivot bolt 218 further engages the detent 211 causing thedownlock mechanism 208 to rotate so as to release the follower pin 168from the locking notch 213.

With reference now to FIG. 11 c, as the roller sleeve 194 is furthercompressed into the sleeve housing 198, the follower pin 168 continuesto travel along the cam slot 216 until eventually reaching a rear wall217 of the cam slot 216, whereupon the cam mechanisms 214 begin totransfer the compression force to the follower pin 168, thereby inducinga torquing moment on the jockey arm assembly causing it to rotate aboutits pivot point 167.

As shown in FIG. 11 d, as the roller sleeve 194 continues to becompressed into the sleeve housing 198, the compression force istransferred to the follower pin 168 via the cam mechanisms 214, causingthe jockey wheel assembly to further rotate and retract towards thelinkage arm. A counter-weight auto center mechanism 162 attached to thejockey wheel assembly may be utilized to bias the alignment of thejockey wheel 160 as it is retracted. As noted previously, thecompression latch mechanism 190 is eventually compressed into the sleevehousing 198 until the center pin bolt 192 impinges on the rear wall 201of the alignment slot 200. At this point, the roller bearing 191 isfully seated in the notch 247 and the ramp receiver bracket 246 iscaptured laterally between the walls of the sleeve housing 198.Correspondingly, the jockey wheel assembly is fully retracted and heldin place by the relative position of the compression latch mechanism 190within the sleeve housing 198.

The compression latch mechanism is biased as it is compressed into itssleeve housing, so that when the accessory towing apparatus isdisengaged from the towing vehicle, the compression latch mechanismautomatically expands out of its sleeve housing, thereby causing thejockey wheel assembly to automatically extend. It is noted that thebiasing mechanism 204 of the compressive latch mechanism 190 provides abiased force by which the system automatically extends the jockey wheelassembly as the accessory towing apparatus 100 is separated from thehitch assembly 200 in reverse of the sequence depicted from FIGS. 11a-d.

It will now be evident to those skilled in the art that there has beendescribed herein an improved trailer towing system for towinggooseneck-type trailers, which enhances the utility, stability andsafety of the hitched vehicle and trailer.

Although the invention hereof has been described by way of a preferredembodiment, it will be evident that other adaptations and modificationscan be employed without departing from the spirit and scope thereof. Theterms and expressions employed herein have been used as terms ofdescription and not of limitation; and thus, there is no intent ofexcluding equivalents, but on the contrary it is intended to cover anyand all equivalents that may be employed without departing from thespirit and scope of the invention.

1. An accessory towing apparatus for linking a vehicle and a goosenecktrailer, comprising in combination: an axle assembly having a pluralityof ground engaging wheels disposed thereon; a framework attached to saidaxle assembly, said framework having three linkage arms extendingtherefrom and a hitch mechanism mounted thereon, said hitch mechanismbeing operable for coupling said trailer to said framework, wherein eachof said linkage arms includes a distal end having a latching mechanismincorporated therein and operable to pivotally connect to said vehicle,said latching mechanisms comprising at least one gate latch mechanismand one compression latch mechanism; wherein each of said linkage armsis operable to pivotally connect to said vehicle along a substantiallycommon axis that is fixed relative to said vehicle.
 2. The accessorytowing apparatus of claim 1, wherein said linkage arms are substantiallyparallel to one another.
 3. The accessory towing apparatus of claim 1,further comprising a receiver hitch mechanism attached to said vehicle,said receiver hitch mechanism comprising a framework attached to a mainframe of said vehicle, having three receiver boxes, which are eachoperable for receiving a receiver bracket that corresponds to one ofsaid latching mechanisms.
 4. The accessory towing apparatus of claim 1,wherein said gate latch mechanism is operable to pivotally attach to agate rod assembly connected to said vehicle.
 5. The accessory towingapparatus of claim 4, wherein said compression latch mechanism includesa roller bearing operable to engage a ramp bracket connected to saidvehicle.
 6. The accessory towing apparatus of claim 1, furthercomprising a cam mechanism pivotally attached to said compression latchmechanism, said cam mechanism connecting said compression latchmechanism to a jockey wheel assembly, which is pivotally attached to oneof said linkage arms, wherein said cam mechanism induces a torquingmoment on said jockey wheel assembly as said roller bearing engages saidramp bracket.
 7. The accessory towing apparatus of claim 1, wherein saidhitch mechanism comprises a ball hitch mechanism.
 8. The accessorytowing apparatus of claim 1, wherein said hitch mechanism comprises afifth-wheel hitch.
 9. The accessory towing apparatus of claim 1, whereinsaid hitch mechanism is mounted on a saddle attached to a first andsecond longitudinal rail of said framework.
 10. The accessory towingapparatus of claim 9, wherein said saddle is selectively attached tosaid longitudinal rails of said framework.
 11. The accessory towingapparatus of claim 9, wherein said saddle further includes a structuralextension framework that vertically extends said hitch mechanism abovesaid saddle.
 12. The accessory towing apparatus of claim 1, wherein saidwheels are fixably aligned with said axle assembly.
 13. The accessorytowing apparatus of claim 1, wherein said axle assembly comprises adynamically aligned axle assembly.
 14. The accessory towing apparatus ofclaim 1, further including an alignment and attachment system comprisinga yoke assembly slidably coupled to a first and second outboard linkagearms, said yoke assembly connected to a winch mechanism attached to saidframework and having two alignment chains extending therefrom, whereinwhen said alignment chains are attached to said vehicle, said system isoperable for centering said linkage arms on rear of said vehicle anddrawing said towing apparatus towards said vehicle.
 15. The accessorytowing apparatus of claim 1, wherein said axle assembly furthercomprises a power take off mechanism connected to an accessory powermechanism.
 16. The accessory towing apparatus of claim 15, wherein saidaccessory power mechanism is a hydraulic pump.
 17. The accessory towingapparatus of claim 15, wherein said accessory power mechanism is anelectrical generator.
 18. An accessory towing apparatus for linking avehicle and a gooseneck trailer, comprising in combination: an axleassembly having a plurality of ground engaging wheels disposed thereon;a framework attached to said axle assembly, said framework having threelinkage arms extending therefrom and a hitch mechanism mounted thereon,said hitch mechanism being operable for coupling said trailer to saidframework, wherein each of said linkage arms includes a distal endhaving a latching mechanism incorporated therein and operable topivotally connect to said vehicle; and a receiver hitch mechanismattached to said vehicle, said receiver hitch mechanism comprising aframework attached to a main frame of said vehicle, having threereceiver boxes, which are each operable for receiving a receiver bracketthat corresponds to one of said latching mechanisms; wherein each ofsaid linkage arms is operable to pivotally connect to said vehicle alonga substantially common axis that is fixed relative to said vehicle. 19.The accessory towing apparatus of claim 18, wherein said linkage armsare substantially parallel to one another.
 20. The accessory towingapparatus of claim 18, wherein said latching mechanisms comprise atleast one gate latch mechanism and one compression latch mechanism.